Bulk hydrogen density

Figure 15. Transverse and time average of the oxygen and hydrogen density, as a function of distance from the center of the metal slab, with the left and right sides of the unit cell averaged together. The horizontal line indicates the density that would correspond to bulk water (with 1 g/cm3). From Ref. 52, by permission.

Charge 3 Hydrogen Content, % Bulk Density Hydrogen Density Increase in Count Rate by Fast Neutron Moderation, % Decrease in Count Rate by Thermal Neutron Transmission, %... 

The volumetric hydrocarbon productivity for bulk hydrogenated ZrFeHo.s intermetallide and the most active composite samples within the 40 % ZrFeH/PA-HP series is nearly identical (-670-690 g/lxh, Fig. 15), which is equal to 48-49 mole CO/lxh. For the isothermal plug-flow reactor at GHSV 7000 h", this yields the efficient FTS rate constant k 420 h". An apparent density of the composite containing 40 % wt. of AC is approximately 3 times lower than that of the bulk intermetallide. Therefore, a volume AC fraction is about 1/7 and k value, referred to it, is, respectively, -2900 h". ... 

Yet there is little consensus - and sometimes plain contradiction - about what structure-making and -breaking actually entails. Does structure-making render water denser, or does it, in making water more ice-like, actually reduce the density More to the point, this concept lacks any real evidence from experimental studies of the structure of electrolyte solutions that significant changes to the bulk hydrogen-bonded network of water really do occur in the presence of salts. 

Example 8 Estimation of Rate Coejficient Estimate the rate coefficient for flow of a 0.01-M water solution of NaCl through a bed of cation exchange particles in hydrogen form with e = 0.4. The superficial velocity is 0.2 cm/s and the temperature is 25 C. The particles are 600 im in diameter, and the diffusion coefficient of sodium ion is 1.2 X 10 cmVs in solution and 9.4 X 10 cmVs inside the particles (of. Table 16-8). The bulk density is 0.7 g dry resin/cnd of bed, and the capacity of the resin is 4.9 mequiv/g dry resin. The mass action eqiiihbrium constant is 1.5. 

The simulated free surface of liquid water is relatively stable for several nanoseconds [68-72] because of the strong hydrogen bonds formed by liquid water. The density decrease near the interface is smooth it is possible to describe it by a hyperbolic tangent function [70]. The width of the interface, measured by the distance between the positions where the density equals 90% and 10% of the bulk density, is about 5 A at room temperature [70,71]. The left side of Fig. 3 shows a typical density profile of the free interface for the TIP4P water model [73]. 

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